<local:CheckViewModel 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"       
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:Bingootest1" 
    
    <local:CheckViewModel.Items>
        <local:ItemViewModel Text="S1" />
        <local:ItemViewModel Text="Technology"/>        
    </local:CheckViewModel.Items>
    
</local:CheckViewModel>